Porsche is yet again under investigation in Germany, this time for alleged tax debts with regards to early retirees and taxable benefits offered to former top executives, including its former CEO, Matthias Mueller.

According to Bild am Sonntag, enforcement officers already visited Porsche late last year, while a company spokesman said that the automaker had already responded to “possibly anticipated tax payments via safety surcharges and lump sum payments,” reports Autonews.

The German outlet has been investigating paperwork related to parties, private travel by managers on company planes and chauffeured cars, as well as discrepancies in payments to tax authorities over salaries collected by former Porsche employees on early retirement schemes.

There’s also a claim that a birthday party held by Mueller, who ran the company between 2015 and 2018, had required retroactive tax declaration, as well as the late settlement of outstanding liabilities.

Porsche however said that it has already paid significant outstanding sums and has handed over all documentation regarding possible tax liabilities for certain employees in early retirement. Investigators looked into payments between 2009 and 2017, prompting an onsite search at the automaker’s headquarters in June of 2018.

The Stuttgart-based automaker has also responded to questions regarding its tax liabilities by launching its own internal tax compliance measures and processes, aided by external consultants.

Prior investigations into Porsche were initiated in connection with the alleged use of a defeat device in V6-powered Cayenne models (June 2017), but also with regards to fraud and false advertising (July 2017) in the wake of the Dieselgate scandal.